Normalized Score breakdown

I'M looking for a breakdown of how the normalized score is brokendown. Went a got the Bts xpac yesterday and played my first game on only chieften to get a feel for it. Won the Space race in the 1940s and my normalized score came out triple of what i had on any game before this xpac was installed. Considereing The difficulty level I was quite shocked and actually kinda disappointed to get such a good score on such a easy level. Prior games i was lucky to make it like 4 or 5 guys up the list on the leaders comparison at end, but this particular game had my compared to the top guy and at 15000 score. So im looking for a breakdown of how the scoring works, And Some peoples average scores on some higher levels to know if this was really that good. What kinda score are you looking at on Prince and above. Thanks